In 1905, as part of his Special Theory of Relativity, Albert Einstein published the point that a large amount of energy could be released from a small amount of matter. This was expressed by equation E = me 2(energy = mass times the speed of light squared). But bombs were not what Einstein had in mind when he published this equation.

    In 1929, he publicly declared that if a war broke out he would “refused to do war service, direct or indirect…” His position would change in 1933, as the result of Adolf Hitler's coming into power in Germany.

    Einstein's greatest role in the invention of the atomic bomb was signing a letter to President Franklin Roosevelt urging that the bomb be built because some physicists feared that Germany might be working on an atomic bomb. Among those concerned were physicists Leo Szilard and Eugene Wigner. But Szilard and Wigner had no influence with those in power. So in July 1939 they explained the problem to someone who did: Albert Einstein. After talking with Einstein, in August 1939 Szilard wrote a letter to President Roosevelt with Einstein's signature on it, which was delivered to Roosevelt in October 1939.

    Germany has invaded Poland the previous month; the time was ripe for action. That October research of a-bomb began but proceeded slowly because the invention of the atomic bomb seemed distant and unlikely. In April 1940 an Einstein letter, ghost-written by Szilard, pressed the researchers on the need for “greater speed”.

    As the realization of nuclear weapons grew near, Einstein looked beyond the current war to future problems that such weapons could bring. He wrote to his friend about his fear about the future use of the a-bomb.

    The atomic bombings of Japan occurred three months after Germany gave in.

In November 1954, five months before his death, Einstein summarized his feelings about his role in the creation of the atomic bomb: “I made one great mistake in my life… when I signed a letter to President Roosevelt recommending that atom bombs be made; but there was some justification—- the danger that the Germans would make them”.

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    "Hey, little boy, will you support me when I'm getting old?" Wang Wenshan, 35, asked his newborn baby as he hugged him at home.

    The Chinese tradition of raising sons to support parents in their old age has been weakened by the rapidly growing economy and improved standard of living. As is the case with more and more developed countries, China faces an aging society. People are living longer and having fewer children. Therefore, many Chinese families are falling into a 4-2-1 family pattern: a couple raises one child and supports four elderly parents. But few realize that a problem is likely to happen ahead.

    The aging of the population is a trend that now affects a growing number of countries. The Information Office of the State Council, China's cabinet, issued（发行） a white paper on measures China has been taking to help its elderly population. The paper said China's population entered the aging period at the end of the 20th century and the proportion of people aged 60 and above accounted for over 10 percent of the entire population. By the end of 2005, China had nearly 144 million people over 60, accounting for 11 percent of the population, according to the white paper.

An expanding aged population inevitably means that many issues must be settled, as the problem concerns every aspect of society. It puts more pressure on each family, causing disturbing economic consequences and serious social problems. It also challenges the labor force supply and the pension system.

    "I used to think that it's not an issue for me to provide for the aged," said Wang, whose parents and parents-in-law all enjoy pensions and medical insurance. But last year Wang's father suffered from a serious illness and afterward Wang began to feel the pressure on his shoulders.

    After his father recovered, Wang opened a bank account for each parent and put away some money in the account every month to prepare for future uncertainties. In addition, he has to save money every month to provide for his son's future education. "I'm now breaking my back to support my family: saving pensions for the parents, my son's education funds, and living costs."

    Wang also bought some commercial old-age insurance for himself. "We have to take precautions（预防） before it is too late, and many of my colleagues share the same view," he said.

    Once there was an 11-year-old boy who went fishing with his father in the middle of the Finger lake. On the day before salmon(鲑鱼) season opened, they were fishing early in the evening, catching other fish with worms. Then the boy tied on a small silver lure (鱼饵) and put it into the lake. Suddenly he felt that something very big pulling on the lure. His father watched with admiration as the boy skillfully brought the fish beside the bank. Finally he lifted the tired fish from the water. It was the largest one he had ever seen, but it was a salmon.

    The boy and his father looked at the big fish. The father lit a match and looked at his watch. It was 10 pm – two hours before the season opened. He looked at the fish, then at the boy. “You'll have to put it back, son,” he said.

    “Dad!” cried the boy, “There will be other fish,” said his father. “Not as big as this one,” cried the boy. He looked around the lake. No other fishermen or boats were in sight in the moonlight. He looked again at his father.

    Even though no one had seen them, nor could anyone ever know what time he had caught the fish, the boy could tell from his father's voice that the decision couldn't be changed. He threw the huge salmon into the dark water. The big fish disappeared. The boy thought that he would never again see such a big fish.

    That was 34 years ago. Today the boy is an successful architect in New York City. He often takes his own son and daughters to fish at the same place.

    And he was right. He has never again caught such a large fish as the one he got that night long ago. But he does see that same fish … again and again … every time he has an ethical (伦理的，道德的) decision to make. For, as his father had taught him, ethics are simple matters of right and wrong. It is only the practice of ethics that is difficult.

    Chinese researchers say they have come up with a simple way to find out a person's biological age —how much the body has aged physically – through a urine (尿) test.

    Their findings will help researchers conduct numbers of ageing studies and even predict a person's risk of age-related diseases, according to a paper published in the journal Frontiers in Ageing Neuroscience.

    Another paper by researchers at the Beijing Hospital and the West China Hospital in Chengdu, Sichuan province, said on Tuesday that people aged at different rates due to changes in their genetic make-up and their environment.

    Chronological age – which is based on one's birth date —was not an exact measure of biological age so a more exact method was needed, the team said.

    Ageing is driven by the lifelong gradual accumulation(积累) of a broad variety of molecular (分子) faults in the body's cells. The team said they had identified a matter 8-oxoGsn that indicated increases in oxidative (氧化性) damage in urine as people's bodies aged.

    Cai Jianping, a co-author at the Beijing Hospital, said: “As we age, we suffer increasing oxidative damage and so the levels of oxidative matters increase in our body.” The team tested the levels of 8-oxoGsn in urine samples from 1,228 Chinese people aged two to 90 and concluded the marker helped accurately determine the stage of biological ageing in adults.

    They had previously found that 8-oxoGsn levels also increased with age in the urine of animals such as mice.

    The team has also developed a rapid analysis technique called ultra-high-performance liquid chromatography(层析法), which can process up to 10 urine samples an hour, according to the study.

    For Kim Duffy, sending away her teenage daughter was the best hope for saving the girl's life.

    Corinne, then 17, had been struggling with bulimia (贪食症) and anorexia (厌食症) for more than five years. Duffy and her husband, Terry, found a residential facility in Virginia, and Corinne signed on for a two-month stay in the summer of 2009.

    Today, Corinne's healthy and pursuing a master's degree in Colorado. She and her parents believe the holistic (整体) approach and individualized focus were key to her recovery. And they know they had access to unique resources. "We were fortunate," says Duffy. "We could pay for everything."

    But many can't. According to a report released in November 2014 by the Standing Committee on the Status of Women, between 600, 000 and one million Canadians suffer from an eating disorder. Public in patient programs often won't admit patients until they're in life-threatening condition. Private clinics often have a long waitlists and high costs-at Homewood, in Guelph, Ont., a room is $ 305 to $360 per day.

    The Duffs' struggle led then to connect other families with the quality of care they received in the United Sates. In late 2013, hey founded the WaterStone Clinic, a private eating disorder center in Toronto.

    Since the facility opened, 170 clients have received treatment. They take yoga, do art therapy and participate in meal preparation, building real-life skills with a support team. Programs run weekdays from 8 a. m. to 2 p. m., and notably, so far WaterStone has no waiting list.

    But this approach is costly: approximately $650 per day. Realizing that the price tag puts WaterStone out of reach for many, the Duffys created the WaterStone Foundation-a charity that provides aid to patients who can't afford treatment the following year. Candidates are assessed by two committees that make a decision based on clinical and financial need. Since 2014, the foundation has helped 100 people.

    Duffy also wants to change the public system. In June of this year, the foundation awarded ＄170, 000 to four Ontario hopitals offering creative treatment to eating disorder patients. "Yes, people need private treatment," she says, "but it's important to help out on a broader scale, too."

    In choosing a friend，one should be very careful. A good friend can help you study. You can have fun together and make each other happy. Sometimes you will meet fair weather friends. They will be with you as long as you have money or luck, but when you are down, they will run away. How do I know when I have found a good friend? I look for certain qualities (品质) of character, especially understanding, honesty and reliability (可靠).

    Above all else, I look for understanding in a friend. A good friend tries to understand how another person is feeling. He is not quick to judge. Instead, he tries to learn from others. He puts himself in the other person's place, and he tries to think of ways to be helpful. He is also a good listener.

    At the same time, however, a good friend is honest. He does not look for faults (过错) in others. He notices their good points. In short, a friend will try to understand me and accept me.

    Another quality of a friend is reliability. I can always depend on (信赖) a good friend. If he tells me he will meet me somewhere at a certain time, I can be sure that he will be there. If I need a favor, he will do his best to help me. If I am in trouble, he will not run away from me.

    There is a fourth quality that makes a friend special. A special friend is someone with whom we can have fun. We should enjoy our lives, and we would enjoy our friendship. That is why I especially like friends who are fun to be with. A good friend likes the same things I like. We share experience (经验) and learn from each other. A good friend has a good sense of humor (幽默), too. He likes to laugh with me. That is how we share in the joy of being friends. And I know that he is looking for the same quality in me.

    When I meet someone who is reliable, honest, and understanding, I know I've found a friend!